Web servers are widely used to host websites accessible to clients via the Internet. The primary function of a web server is to deliver requested web pages to clients using Hypertext Transfer Protocol (HTTP). In a typical scenario, a client sends an HTTP requests to the web server. The web server then sends to a response to the client that includes the requested web page. The web page typically is delivered using an HTML document and any additional content that may be included with a document, such as images, style sheets and scripts.